This proposal describes a 5-year training program for the development of an academic career in Investigative Pathology. The principal investigator has completed structured residency training in Anatomic Pathology at Columbia University and obtained a PhD in Virology at the University of Amsterdam. He has a strong track record in pathobiology and assay design and will expand his scientific skills in genetics, biochemistry, and computational biology, and knowledge of neurodegenerative diseases over the course of the award period. This training program has been designed to ensure command of RNA molecular biology as applied to neurodegenerative disease research. Prof. Thomas Tuschl will mentor the principal investigator's scientific development. Prof. Tuschl is a pioneer in the field of post-transcriptional regulation of gene expression/small RNA biology. He is Professor of Biochemistry at The Rockefeller University and has trained and guided several postdoctoral fellows to independent research positions. Training activities will be enhanced through focused instruction in neurogenetics and neuropathology. In addition, a scientific advisory committee, composed of exceptional basic and physician scientists, has been formed to provide scientific and career advice. Research will focus on post-transcriptional regulation of gene expression in major TDP-43 diseases. Although TDP-43, an RNA-binding protein, forms protein aggregates, it is currently unclear whether post- transcriptional RNA dysregulation is also a significant pathogenetic mechanism. The long-term goal is to investigate post-transcriptional regulation of gene expression in neurodegenerative diseases, focusing on major TDP-43 diseases in this application. The central hypothesis is that post-transcriptional RNA dysregulation is a key pathogenetic mechanism in major TDP-43 diseases. This hypothesis will be tested by pursuing 3 specific aims to: (1) identify RNA targets and examine RNA regulatory functions of wild-type and mutant TDP-43 in Flp-In cell lines (2) assess miRNA regulatory networks in major TDP-43 disease tissues and Flp-In cell lines and (3) estimate sequence variation in TDP-43 RNA-binding regions and TDP-43- and/or miRNA-targeted sites in persons with and without major TDP-43 diseases. This approach is innovative because it uses advanced methods, such as Photoactivatable Ribonucleoside-Crosslinking and Immunoprecipitation (PAR-CLIP), recently developed in the applicant's laboratory. The proposed research is significant because identification of RNA targets and regulatory functions of wild-type and mutant TDP-43, assessment of miRNA regulatory networks, and delineation of targeted transcripts and sequence variations, will collectively yield key pathogenetic insights into common and devastating illnesses of aging populations. The Laboratory of RNA Molecular Biology, Rockefeller University is an ideal setting for intensive training in a set of highly specialized scientific skills required to address a complex area of pathobiology. This environment will prepare the principal investigator for an academic career in investigative pathology. PUBLIC HEALTH RELEVANCE: The proposed research is relevant to public health because it addresses an underestimated disease mechanism in a set of devastating and untreatable brain diseases, termed major TDP-43 diseases, which are common in aging populations. This research is relevant to NIH's mission to pursue fundamental knowledge and goal to foster innovative research strategies and their applications to advance the Nation's capacity to protect and improve health.